CTE prevalent in deceased players, study shows

Researchers with the Department of Veterans Affairs and Boston University released findings today that 96 percent of deceased NFL players and 79 percent of all deceased football players tested positive for chronic traumatic encephalopathy.

CTE is a disease believed to be caused by repetitive trauma to the head and can lead to memory loss, depression and dementia. The study sheds light on the concussion problem the NFL has been struggling with -- especially as scientists and doctors learn more about the game's effects later in life.

Below are visualizations breaking down concussions in the NFL by year and position.